Work Tool Coupler Engagement System

ABSTRACT

A coupling device may include a coupler frame a variable length actuator having a right actuator end and a left actuator end supported by the coupler frame and extending between the ends of the coupler frame. Right and left latches are slidably engaged by and movable relative to the coupler frame and are operatively connected to the ends of the variable length actuator. The variable length actuator operates to move between retracted and extended positions and may be slidably mounted on the coupler frame so that ends move horizontally relative to the coupler frame and the variable length actuator does not move vertically relative to the coupler frame. The latches move relative to the coupler frame between unlocked and locked positions as the variable length actuator moves between the actuator retracted and extended positions, respectively.

TECHNICAL FIELD

The present disclosure relates generally to a quick coupling device for a tool/implement for a machine and, more particularly, to a quick coupling device that may be actuated by the operator from the cab of the machine.

BACKGROUND

Machines frequently have lift arms with work tools or implements disposed at the ends of the lift arms. The work tools or implements may include buckets, blades, forks and the like. To simplify and expedite the exchanging or replacement of such tools, the lift arms are typically equipped with an attachment frame that includes a coupling device for quickly coupling and decoupling the various implements from the attachment frame. Some of these coupling devices may also be power-operated to reduce the necessity for manual intervention and for ease of operation. Further, some coupling devices may be actuated from inside a cab of the machine by an operator.

In U.S. Pat. Appl. Publ. No. 2014/0096419 published on Apr. 10, 2104, to Pinther et al. entitled “Work Tool Coupler Linkage,” an electrically actuated coupling device for a machine and an implement is disclosed. The device includes a frame and an electric motor coupled to a drive shaft that extends between right and left ends of the frame. The motor causes the shaft to extend or retract from each end of the frame. Each end of the frame includes a guide for receiving a latch. Each latch is pivotally coupled to a spring and each spring is pivotally coupled to a specially shaped lever which is pivotally coupled to the frame as well as an end of the shaft. The electric motor may be activated by the operator from within the cab.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a coupling device for coupling an implement to a machine is disclosed. The coupling device may include a coupler frame having a right frame end and a left frame end, and a variable length actuator having a right actuator end and a left actuator end and extending between the right frame end and the left frame end of the coupler frame. The variable length actuator may be operable to move between an actuator retracted position and an actuator extended position and may be slidably mounted on the coupler frame so that the right actuator end and the left actuator end move horizontally relative to the coupler frame and the variable length actuator does not move vertically relative to the coupler frame as the variable length actuator moves between the actuator retracted position and the actuator extended position. The coupling device may further include a right latch slidably engaged by and movable relative to the coupler frame proximate the right frame end and operatively connected to the right actuator end of the variable length actuator, and a left latch slidably engaged by and movable relative to the coupler frame proximate the left frame end and operatively connected to the left actuator end of the variable length actuator. The right latch and the left latch may move relative to the coupler frame between a latch unlocked position that will not engage the implement when the variable length actuator is in the actuator retracted position and a latch locked position that will engage the implement when the variable length actuator is in the actuator extended position.

In another aspect of the present disclosure, a method of coupling and decoupling an implement to and from a machine having a coupling device connected to lift arms of the machine is disclosed. The method may include moving the machine toward the implement and engaging an implement rear wall of the implement with a coupler frame front wall of a coupler frame, moving the coupling device to cause an implement engaging edge of the coupling device to be inserted into a coupler receiving bracket of the implement, and actuating a variable length actuator to extend to an actuator extended position and to correspondingly cause a right latch and a left latch operatively coupled to the variable length actuator to move to a latch locked position with the right latch and the left latch disposed within latch receiving openings of the implement. The variable length actuator may be operable to move between an actuator retracted position and the actuator extended position and may be slidably mounted on the coupler frame so that a right actuator end and a left actuator end of the variable length actuator move horizontally relative to the coupler frame, and the variable length actuator does not move vertically relative to the coupler frame as the variable length actuator moves between the actuator retracted position and the actuator extended position.

In a further aspect of the present disclosure, a machine is disclosed. The machine may include a cab, a right lift arm, a left lift arm, a coupler frame having a right frame end with the right lift arm coupled thereto and a left frame end with the left lift arm coupled thereto, and a variable length actuator having a right actuator end and a left actuator end and extending between the right frame end and the left frame end of the coupler frame. The variable length actuator may be operable to move between an actuator retracted position and an actuator extended position and may be slidably mounted on the coupler frame so that the right actuator end and the left actuator end move horizontally relative to the coupler frame and the variable length actuator does not move vertically relative to the coupler frame as the variable length actuator moves between the actuator retracted position and the actuator extended position. The machine may further include a right latch slidably engaged by and movable relative to the coupler frame proximate the right frame end and operatively connected to the right actuator end of the variable length actuator, a left latch slidably engaged by and movable relative to the coupler frame proximate the left frame end and operatively connected to the left actuator end of the variable length actuator, and an implement having an implement rear wall engaged by a coupler frame front wall when the implement is coupled to the machine. The right latch and the left latch may move relative to the coupler frame between a latch unlocked position that will not engage the implement when the variable length actuator is in the actuator retracted position and a latch locked position that will engage the implement when the variable length actuator is in the actuator extended position.

Additional aspects are defined by the claims of this patent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a machine having an implement coupled thereto by a coupling device in accordance with the present disclosure;

FIG. 2 is the side view of the machine of FIG. 1 having the implement uncoupled from the coupling device;

FIG. 3 is an isometric view of side and rear walls of the implement of FIG. 1; and

FIG. 4 is a front view of a coupling device in accordance with the present disclosure with latches in a latch locked position;

FIG. 5 is a rear view of the coupling device of FIG. 4 with the latches in a latch unlocked position;

FIG. 6 is the rear view of the coupling device of FIG. 4 with the latches in the latch unlocked position and portions of a coupler frame and an actuator housing removed to reveal linkage assemblies and a variable length actuator;

FIG. 6A is a partially exploded view of a right latch link and a right spring of the coupling device of FIG. 4;

FIG. 7 is the rear view of the coupling device of FIG. 6 with the linkage assemblies and the variable length actuator in an intermediate position;

FIG. 8 is the rear view of the coupling device of FIG. 6 with the latches in the latch locked position;

FIG. 9 is the rear view of the coupling device of FIG. 5 with the latches in the latch locked position; and

FIG. 10 is an enlarged top isometric view of the coupling device of FIG. 4 with a top housing wall of an actuator housing removed.

DETAILED DESCRIPTION

FIG. 1 shows a machine 10 that may be equipped with a coupling device 12 that may be capable of quickly coupling and decoupling a variety of implements 14 to and from the machine 10, such as a bucket as illustrated herein. In the example shown, the machine 10 is a skid steer loader, but the machine 10 may be any work machine where it is desirable to quickly couple and uncouple various work implements and tools. The machine 10 includes a frame 16 that is supported above a work surface by ground engaging elements 18. While the ground engaging elements 18 are wheels in the example shown, this disclosure is applicable to track-type machines as well. The machine 10 may also include right lift arm 20 and a left lift arm 20 that may be spaced apart on opposite sides of the machine 10. The lift arms 20 may raise and lower the coupling device 12 and the implement 14, and may carry actuators (not shown) that may articulate the coupling device 12 and the implement 14 about a horizontal axis. The machine 10 may include an operator station or cab 22 on the frame 16 that may have operator controls (not shown) for controlling actuation mechanisms (not shown) for the coupling device 12, the ground engaging elements 18 and the lift arms 20. The cab 22 may also provide a vantage point for an operator to view the coupling device 12, the implement 14 and a work area (not shown) in which the machine 10 is operating.

Turning to FIG. 2, the machine 10 is illustrated with the implement 14 decoupled from the coupling device 12. The implement 14 is shown in greater detail in FIG. 3. The coupling device 12 may include a coupler frame 24 that is connected to the lift arms 20. The coupler frame 24 may include an implement engaging edge 26 that may be received by a coupler receiving bracket 28 mounted on an implement rear wall 30 of the implement 14. The coupling device 12 may further include a right latch 32 and a left latch 34 that are slidably engaged by and movable relative to the coupler frame 24. The right latch 32 and the left latch 34 may move relative to the coupler frame 24 between a latch locked position as shown in FIG. 2 where they will engage the implement 14 and a latch unlocked position where they are retracted into the coupler frame 24 and will not engage the implement 14. When in the latch locked position after the coupler frame 24 is moved into engagement with the implement rear wall 30 with the implement engaging edge 26 inserted into the coupler receiving bracket 28, the right latch 32 and the left latch 34 may be received in a right latch receiving opening 36 and a left latch receiving opening 38, respectively, to lock the implement 14 to the coupling device 12 while the machine 10 performs work in the work area. The coupler receiving bracket 28 and the latch receiving openings 36, 38 are exemplary only, and other connection mechanisms are contemplated for engagement between the coupling device 12 and the implement 14 so that the latches 32, 34 can engage and disengage corresponding elements of the implement 14. The implement 14 may further include a step bracket 40 attached proximate a top end of the implement 14 and having a no-slip edge 42 that may be used as a step by an operator of the machine 10 for climbing up to and down from the cab 22 when the implement 14 is coupled to the coupling device 12.

FIG. 4 is a front view of the coupling device 12 with the right latch 32 and the left latch 34 extending from the coupler frame 24 in the latch locked position. The coupler frame 24 may include a coupler frame front wall 50 that may face and engage the implement rear wall 30 when the implement 14 is coupled to the machine 10. The coupler frame 24 may have a right frame end 52 and a left frame end 54 to which the lift arms 20 may be connected to secure the coupling device 12 to the machine 10. The right latch 32 may be disposed and slidable within a right latch guide 56 proximate the right frame end 52 and the left latch 34 may be disposed and slidable within a left latch guide 58 proximate the left frame end 54 so that the latches 32, 34 are spaced apart to form a stable connection of the coupling device 12 to the implement 14. The coupler frame 24 may further include an actuator housing 60 enclosing an actuator (hidden) of the coupling device 12 that may actuate to cause the right latch 32 and the left latch 34 to move between the latch locked position and the latch unlocked position. The actuator housing 60 may include a housing front wall 62 having a right horizontal guide slot 64 and the left horizontal guide slot 66 that may receive and engage a right guide pin 68 and a left guide pin 70 that may control movement of the actuator within the actuator housing 60 as described more fully below. The actuator housing 60 may further include a housing top wall 72 that may be removable to provide access to the actuator disposed therein. The housing top wall 72 may have a step plate 74 extending upwardly therefrom and having a no-slip edge 76 that may be used as a step by an operator of the machine 10 for climbing up to and down from the cab 22 when the implement 14 is not coupled to the coupling device 12.

Referring to the rear view of FIG. 5, the coupling device 12 is shown in the latch unlocked position with the right latch 32 and the left latch 34 retracted into the right latch guide 56 and the left latch guide 58, respectively. The coupling device 12 may include a right linkage assembly 80 connecting the right latch 32 to the right guide pin 68, and a left linkage assembly 82 connecting the left latch 34 to the left guide pin 70. The right guide pin 68 and the left guide pin 70 may extend through a housing rear wall 84 of the actuator housing 60. The right guide pin 68 may be disposed within a right horizontal guide slot 86 through the housing rear wall 84 that corresponds to the right horizontal guide slot 64 through the housing front wall 62, and the left guide pin 70 may be disposed within a left horizontal guide slot 88 through the housing rear wall 84 that corresponds to the left horizontal guide slot 66 through the housing front wall 62. As the right guide pin 68 and the left guide pin 70 move horizontally within the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88, respectively, the right linkage assembly 80 and the left linkage assembly 82 will correspondingly move the right latch 32 and the left latch 34, respectively, between the latch unlocked position shown in FIG. 5 and the latch locked position shown in FIG. 4 as described more fully hereinafter.

FIGS. 6-8 illustrate the coupling device 12 with portions of the coupler frame 24 and the actuator housing 60 removed to show the interior of the actuator housing 60, the right linkage assembly 80 and the left linkage assembly 82 in greater detail. The actuator housing 60 encloses a variable length actuator 90 that may extend between the right frame end 52 and the left frame end 54 of the coupler frame 24. The variable length actuator may have a right actuator end 92 to which the right guide pin 68 is connected and a left actuator end 94 to which the left guide pin 70 is connected to support the variable length actuator 90 within the actuator housing 60. The variable length actuator 90 may be operable to move between an actuator retracted position (FIG. 6) in which the actuator ends 92, 94 and the guide pins 68, 70 are separated by a retracted distance causing the linkage assemblies 80, 82 to move the right latch 32 and the left latch 34 to the latch unlocked position, and an actuator extended position (FIG. 8) in which the actuator ends 92, 94 and the guide pins 70 are separated by an extended distance causing the linkage assemblies 80, 82 to move the right latch 32 and the left latch 34 to the latch locked position.

The variable length actuator 90 may be any appropriate actuator capable of varying a linear distance between the right guide pin 68 and the left guide pin 70 as they slide horizontally within the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88. In the illustrated embodiment, the variable length actuator 90 may be an extendable shaft assembly having a motor 96 with the left actuator end 94 being a left motor end operatively connected to the left guide pin 70, and a shaft 98 extending from a right motor end 100 of the motor 96 and with the right actuator end 92 being a right shaft end operatively connected to the right guide pin 68. Of course, the variable length actuator 90 could be reversed so that the motor 96 is on the right side of the variable length actuator 90 and the shaft 98 is on the left side. The motor 96 may be actuatable to retract the shaft 98 to move the extendable shaft assembly to the actuator retracted position and to extend the shaft 98 to move the extendable shaft assembly to the actuator extended position. The extendable shaft assembly illustrated herein is exemplary of the variable length actuators 90 that may be implemented in the coupling device 12 in accordance with the present disclosure. For example, the electric motor 96 described herein may be replaced with a hydraulic cylinder capable of extending and retracting to move the right guide pin 68 and the left guide pin 70. Other types of arrangements capable of converting a motion of an actuator into horizontal movement of the right guide pin 68 and the left guide pin 70 within the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88 are contemplated by the inventors.

As discussed above, the right linkage assembly 80 may operatively connect the right guide pin 68 and, correspondingly, the right actuator end 92 to the right latch 32. The right linkage assembly 80 may include a right lever 110 pivotally mounted to the coupler frame 24 proximate the right frame end 52 by a pivot pin 112. A right actuator link 114 may be connected between the right actuator end 92 and the right lever 110. The right actuator link 114 may be pivotally connected to the right actuator end 92 by the right guide pin 68, and to the right lever 110 by a pivot pin 116. A right latch link 118 may be connected between the right latch 32 and the right lever 110, with the right latch link 118 being pivotally connected to the right latch 32 by a pivot pin 120, and pivotally connected to the right lever 110 by a pivot pin 122.

A right spring 124 may be disposed on the right latch link 118 between the right latch 32 and the right lever 110, and may bias the right latch 32 away from the right lever 110. The arrangement of the right latch link 118 and the right spring 124 is shown in greater detail in the partially exploded view of FIG. 6A. The right latch link 118 may include a hole 126 there through at a first end that will receive the pivot pin 120 to pivotally connect the right latch link 118 to the right latch 32. The right latch link 118 may further include an axially extending slot 128 there through at a second end opposite the first end that will receive the pivot pin 122 to pivotally connect the right latch link 118 to the right lever 110. The axially extending slot 128 may allow the pivot pin 122 to slide therein so that a distance between the pivot pins 120, 122 may vary as the right linkage assembly 80 moves the right latch 32 between the latch unlocked position and latch locked position. The right spring 124 may be disposed on the right latch link 118 and between the pivot pins 120, 122 so that the right spring 124 applies a force biasing the pivot pins 120, 122 and, correspondingly, the right latch 32 and the right lever 110 apart, with the force increasing as the distance between the pivot pins 120, 122 decreases and the right spring 124 is compressed. Washers 130, 132 may be disposed at both ends of the right spring 124 to provide engagement surfaces between the right latch 32 and the right lever 110, and the ends of the right spring 124. As will be discussed further below, the arrangement of the right latch link 118 and the right spring 124 may allow a degree of relative linear movement of the right latch 32 and the right lever 110 that may protect the components of the coupling device 12 from unintended displacements of the right latch 32.

Returning to FIG. 6, the left linkage assembly 82 may operatively connect the left guide pin 70 and the left actuator end 94 to the left latch 34 in a similar manner as the right linkage assembly 80 connects the right guide pin 68 to the right latch 32. The left linkage assembly 82 may include a left lever 140 pivotally mounted to the coupler frame 24 proximate the left frame end 54 by a pivot pin 142. A left actuator link 144 may be connected between the left actuator end 94 and the left lever 140. The left actuator link 144 may be pivotally connected to the left actuator end 94 by the left guide pin 70, and to the left lever 140 by a pivot pin 146. A left latch link 148 may be connected between the left latch 34 and the left lever 140, with the left latch link 148 being pivotally connected to the left latch 34 by a pivot pin 150, and pivotally connected to the left lever 140 by a pivot pin 152. The left latch link 148 may have a similar configuration as the right latch link 118 as illustrated and described above, and have a left spring 154 disposed thereon and providing a force biasing the left latch 34 away from the left lever 140.

The movement of the right latch 32 and the left latch 34 from the latch unlocked position to the latch locked position is show in the sequence of FIGS. 6-8. Referring to FIG. 6, with the variable length actuator 90 in the actuator retracted position, guide pins 68, 70 are separated by a minimum distance and are proximate inner ends of the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88. With the guide pins 68, 70 pulled toward each other, the right actuator link 114, and the left actuator link 144 rotate the right lever 110 and the left lever 140 inwardly toward the variable length actuator 90. The right lever 110 and the left lever 140 cause the right latch link 118 and the left latch link 148 to pull upwardly on the right latch 32 and the left latch 34, causing the latches 32, 34 to slide upwardly in the right latch guide 56 and the left latch guide 58 to the latch unlocked position.

When the variable length actuator 90 is actuated to extend the shaft 98, the guide pins 68, 70 begin to move horizontally relative to the coupler frame 24 due to the constraints of the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88 as shown in FIG. 7. The right actuator link 114 and the left actuator link 144 cause the right lever 110 and the left lever 140 to rotate away from the variable length actuator 90 and toward the right latch 32 and the left latch 34, respectively. The right lever 110 and the left lever 140 may compress the right spring 124 and the left spring 154 against the right latch 32 and the left latch 34 and cause the latches 32, 34 to slide downwardly within the right latch guide 56 and the left latch guide 58 toward the latch locked position and extend outwardly from the coupler frame 24. Due to the constraint of the movement of the right guide pin 68 and the left guide pin 70 in the horizontal direction, the variable length actuator 90 does not move vertically relative to the coupler frame 24 as the variable length actuator 90 moves from the actuator retracted position toward the actuator extended position.

As illustrated in FIG. 7, the right guide pin 68 and the left guide pin 70 have moved approximately the same horizontal distance from their retracted positions as shown in FIG. 6. Correspondingly, the right linkage assembly 80 and the left linkage assembly 82 have moved approximately the same amounts from their retracted positions. However, it is possible for the right guide pin 68 and the left guide pin 70 to move outwardly at different times as the variable length actuator 90 extends toward the actuator extended position. For example, a difference in friction resisting the motion of the right latch 32 and the right linkage assembly 80 versus the left latch 34 and the left linkage assembly 82 may be large enough that the left guide pin 70 may begin moving to the left and the left linkage assembly 82 may begin rotating toward the actuator extended position before the right guide pin 68 begins sliding to the right and the right linkage assembly 80 begins rotating toward the actuator extended position. The left guide pin 70 may continue sliding to the left until the left guide pin 70 is engaged by the outer ends of the left horizontal guide slots 66, 88 or the left spring 154 exerts sufficient force on the left lever 140 that the friction in the right latch 32 and the right linkage assembly 80 is overcome and force in the right guide pin 68 begins rotating the right linkage assembly 80 toward the actuator extended position and forcing the right latch 32 downwardly toward the latch locked position. Similarly, the right guide pin 68 may begin moving outwardly before the left guide pin 70 if the forces resisting the movement of the left latch 34 and the left linkage assembly 82 are greater than the forces on the right latch 32 and the right linkage assembly 80.

As shown in FIG. 7, the right latch 32 and the left latch 34 may be disposed at the latch locked position, but the variable length actuator 90, the right linkage assembly 80 and the left linkage assembly 82 are only at an intermediate position. An impact driving the right latch 32 and/or the left latch 34 upwardly may be communicated through the right linkage assembly 80 and/or the left linkage assembly 82 to the variable length actuator 90 and may cause damage to the actuator 90. Consequently, it may be desirable to further extend the variable length actuator 90 to a fully extended position as shown in FIG. 8 where impacts on the right latch 32 and the left latch 34 will not be transmitted to the variable length actuator 90. With the variable length actuator 90 in the actuator extended position, the right guide pin 68 and the left guide pin 70 are disposed at the outer ends of the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88. During the extension of the variable length actuator 90, the right lever 110, the right latch link 118, the left lever 140 and the left latch link 148 have rotated past a limiting position where the pivot pins 112, 120, 122 are linearly aligned and the pivot pins 142, 150, 152 are linearly aligned. During this movement, the variable length actuator 90 continues maintaining a constant vertical position relative to the coupler frame 24 as the shaft 98 extends from the motor 96. With the elements in the illustrated positions, impacts on the right latch 32 and the left latch 34 are not transmitted to the variable length actuator 90. Instead, when the right latch 32 is impacted, force transmitted through the right latch link 118 and the right spring 124 rotate the right lever 110 in the counterclockwise direction, which will cause the right actuator link 114 to pull the right guide pin 68 outwardly and into engagement with the outer ends of the right horizontal guide slots 64, 86. Similarly, impacts on the left latch 34 will pull the left guide pin 70 outwardly and into engagement with the outer ends of the left horizontal guide slots 66, 88. Under this arrangement, impact loads on the right latch 32 and the left latch 34 are transferred to the actuator housing 60 and the coupler frame 24 instead of to the variable length actuator 90.

FIG. 9 illustrates the rear of the coupling device 12 with the coupler frame 24 and the actuator housing 60 intact. The combined views of FIGS. 5 and 9 illustrate displaying a visual indication at the coupling device 12 of a current position of the variable length actuator 90 and a corresponding latch position of the right latch 32 and the left latch 34. The right guide pin 68 extends through the right horizontal guide slot 86 of the housing rear wall 84, and the left guide pin 70 extends through the left horizontal guide slot 88, and the guide pins 68, 70 are visible external to the coupling device 12 to an operator in the cab 22. When the operator sees the guide pins 68, 70 in the positions shown in FIG. 5, they know that the variable length actuator 90 is in the actuator retracted position and the right latch 32 and the left latch 34 are in the latch unlocked position, and the coupling device 12 can be moved into engagement with the implement 14 to couple the implement 14 to the machine 10, or moved out of engagement with the implement 14 to decouple the implement from the machine 10. When the operator sees the guide pins 68, 70 in the positions shown in FIG. 9, they know that the variable length actuator 90 is in the actuator extended position and the right latch 32 and the left latch 34 are in the latch locked position. At this point, the latch receiving openings 36, 38 should have received the latches 32, 34 if the coupling device 12 is properly engaging the implement rear wall 30 and the implement is coupled to the machine 10. Where one or both of the guide pins 68, 70 are disposed at intermediate positions, the operator knows that the variable length actuator 90 must be retracted before the implement 14 is decoupled from the coupling device 12, or must be extended before the implement 14 is locked and coupled to the coupling device 12.

It is typically necessary to access the variable length actuator 90 within the actuator housing 60 for maintenance and inspection during the useful life of the coupling device 12. For this reason, the housing top wall 72 may be removable to provide access for maintenance personnel. FIG. 10 illustrates a left portion of the actuator housing 60 with the housing top wall 72 removed to expose the motor 96, the left lever 140 and the left actuator link 144. The left guide pin 70 may be configured to receive a retention clip 160 or other securement device that may engage the left actuator link 144 to retain the left guide pin 70 in place and maintain the rotational connection between the left actuator end 94 and the left actuator link 144. The right guide pin 68 and the right actuator link 114 may have a similar configuration. If the variable length actuator 90 requires maintenance or replacement, the retention clip 160 may be removed from the left guide pin 70, and the left guide pin 70 may be removed so that the left actuator end 94 is separated from the left actuator link 144, and the variable length actuator 90 may be lifted out of the actuator housing 60.

If the implement 14 is coupled to the machine 10 when the variable length actuator 90 fails, it may be necessary to manually move the right latch 32 and the left latch 34 from the latch locked position to the latch unlocked position to decouple implement. To assist in moving the left linkage assembly 82, the left actuator link 144 may include an engagement slot 162 configured to receive a prying tool (not shown) for manipulation of the positions of the variable length actuator 90, the left linkage assembly 82 and the left latch 34. The right actuator link 114 may have a similar engagement slot for manipulating the positions of the variable length actuator 90, the right linkage assembly 80 and the right latch 32. Once inserted into the engagement slot 162, the prying tool can be used to rotate the left linkage assembly 82 to slide the left latch 34 to the latch unlocked position and disengage the implement 14.

INDUSTRIAL APPLICABILITY

The coupling device 12 as illustrated and described herein may be used to quickly and easily change the implements 14 on the machine 10, and the activation of the coupling device 12 may be performed by an operator in the cab 22. When the implement 14 is decoupled from the machine 10 as shown in FIG. 2, the operator in the cab 22 can ensure that the variable length actuator 90 is in the actuator retracted position and the right latch 32 and the left latch 34 are in the latch unlocked position by confirming that the guide pins 68, 70 are in the positions shown in FIG. 5. If not, the operator may actuate the variable length actuator 90 to move the guide pins 68, 70 to the actuator retracted position. After ensuring that the latches 32, 34 are in the latch unlocked position, the operator may move the machine 10 toward the implement 14 and engage the implement rear wall 30 with the coupler frame front wall 50. The operator may then operate the coupling device 12 and the lift arms 20 to move the coupling device 12 to cause the implement engaging edge 26 of the coupling device 12 to be inserted into the coupler receiving bracket 28 of the implement 14. The coupling device 12 may be moved through a combination of raising and lowering the lift arms 20 and articulating the coupling device 12 about the horizontal axis until the implement engaging edge 26 is disposed within the coupler receiving bracket 28.

Once the implement engaging edge 26 is disposed within the coupler receiving bracket 28, the operator may actuate the variable length actuator 90 to extend to the actuator extended position and correspondingly cause the right latch 32 and the left latch 34 to move to the latch locked position with the right latch 32 and the left latch 34 extended from the coupler frame 24 and disposed within the latch receiving openings 36, 38 of the implement 14. Due to the engagement of the guide pins 68, 70 by the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88, the variable length actuator 90 may move horizontally relative to the coupler frame 24 and the actuator housing 60 while maintaining a constant vertical position relative to the coupler frame 24. The operator in the cab 22 can confirm that the variable length actuator 90 has reached the actuator extended position and the right latch 32 and the left latch 34 are in the latch locked position and are disposed within the latch receiving openings 36, 38 by confirming that the guide pins 68, 70 are in the positions shown in FIG. 9.

When the operator wants to decouple the implement 14 from the machine 10, the operator may lower the lift arms 20 to place the implement 14 on the work surface, and then actuate the variable length actuator 90 to retract to the actuator retracted position and correspondingly cause the right latch 32 and the left latch 34 to move to the latch unlocked position with the right latch 32 and the left latch 34 withdrawn from the latch receiving openings 36, 38 of the implement 14. The operator can confirm that the right latch 32 and the left latch 34 are in the latch unlocked position and disengaged from the implement 14 by confirming that the guide pins 68, 70 are back in the positions shown in FIG. 5. With the right latch 32 and the left latch 34 unlocked, the implement 14 may be decoupled by moving the coupling device 12 and/or the lift arms 20 to cause the implement engaging edge 26 of the coupling device 12 to move out of the coupler receiving bracket 28 of the implement 14. The movement of the coupling device 12 may be a combination of articulating the coupling device 12 forward and lowering the lift arms 20 and, correspondingly, the coupling device 12. With the implement engaging edge 26 removed from the coupler receiving bracket 28, the operator may back the machine 10 away from the implement 14 to the position shown in FIG. 2, and then reposition the machine 10 to couple a different implement 14.

Due to the environments in which the machine 10 may operate, the coupler frame 24 and the actuator housing 60 may be prone to collecting foreign material and debris, and have the material and debris pack around the variable length actuator 90. The collected material can introduce radial or side loads to the variable length actuator 90 in configurations where the actuator 90 moves vertically relative to the coupler frame 24. Such loads can cause premature failure of the variable length actuator 90. The coupling device 12 in accordance with the present disclosure may reduce the instances of premature failure of the actuator 90. The actuator links 114, 144 and the guide pins 68, 70 constrained to horizontal movement by the right horizontal guide slots 64, 86 and the left horizontal guide slots 66, 88 constrain the variable length actuator 90 to movement horizontally with respect to the coupler frame 24 and prevent vertical movement of the actuator 90. Material accumulation within the actuator housing 60 may not cause side loads on the actuator 90 and consequently eliminate a failure mode of the coupling device 12. When the variable length actuator 90 does fail, however, the interior of the actuator housing 60 is accessible by removing the housing top wall 72, and the positions of the variable length actuator 90 and the latches 32, 34 may be manually adjusted if necessary by engaging the engagement slot 162 of one or both of the actuator links 114, 144 with an appropriate prying tool.

While the preceding text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of protection is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the scope of protection.

It should also be understood that, unless a term was expressly defined herein, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to herein in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning. 

What is claimed is:
 1. A coupling device for coupling an implement to a machine, comprising: a coupler frame having a right frame end and a left frame end; a variable length actuator having a right actuator end and a left actuator end and extending between the right frame end and the left frame end of the coupler frame, the variable length actuator being operable to move between an actuator retracted position and an actuator extended position and being slidably mounted on the coupler frame so that the right actuator end and the left actuator end move horizontally relative to the coupler frame and the variable length actuator does not move vertically relative to the coupler frame as the variable length actuator moves between the actuator retracted position and the actuator extended position; a right latch slidably engaged by and movable relative to the coupler frame proximate the right frame end and operatively connected to the right actuator end of the variable length actuator; and a left latch slidably engaged by and movable relative to the coupler frame proximate the left frame end and operatively connected to the left actuator end of the variable length actuator, wherein the right latch and the left latch move relative to the coupler frame between a latch unlocked position that will not engage the implement when the variable length actuator is in the actuator retracted position and a latch locked position that will engage the implement when the variable length actuator is in the actuator extended position.
 2. The coupling device of claim 1, wherein the coupler frame comprises: a right horizontal guide slot operatively connected to the right actuator end to cause the right actuator end to move horizontally relative to the coupler frame and to prevent the right actuator end from moving vertically relative to the coupler frame; and a left horizontal guide slot operatively connected to the left actuator end to cause the left actuator end to move horizontally relative to the coupler frame and to prevent the left actuator end from moving vertically relative to the coupler frame.
 3. The coupling device of claim 1, wherein the coupler frame comprises an actuator housing enclosing the variable length actuator and having a right horizontal guide slot and a left horizontal guide slot, wherein the variable length actuator comprises a right guide pin connected to the right actuator end and extending through the right horizontal guide slot and a left guide pin connected to the left actuator end and extending through the left horizontal guide slot, and wherein the right horizontal guide slot and the left horizontal guide slot engage the right guide pin and the left guide pin, respectively, to cause the right actuator end and the left actuator end to move horizontally relative to the coupler frame and to prevent the right actuator end and the left actuator end from moving vertically relative to the coupler frame.
 4. The coupling device of claim 3, wherein the right horizontal guide slot and the left horizontal guide slot extend through a housing rear wall of the actuator housing so that the right guide pin and the left guide pin are visible from a position external to the coupling device to provide an operator of the machine with a visual indication of a current position of the variable length actuator between the actuator retracted position with the right latch and the left latch in the latch unlocked position and the actuator extended position with the right latch and the left latch in the latch locked position.
 5. The coupling device of claim 1, wherein the variable length actuator is an extendable shaft assembly comprising: a motor wherein the left actuator end is a left motor end operatively connected to the left latch; and a shaft extending from a right motor end of the motor and wherein the right actuator end is a right shaft end operatively connected to the right latch, wherein the motor is actuatable to retract the shaft to move the extendable shaft assembly to the actuator retracted position and to extend the shaft to move the extendable shaft assembly to the actuator extended position.
 6. The coupling device of claim 1, comprising: a right linkage assembly operatively connecting the right actuator end to the right latch, the right linkage assembly comprising: a right lever pivotally mounted to the coupler frame proximate the right frame end, a right actuator link pivotally connected between the right actuator end and the right lever, and a right latch link pivotally connected between the right latch and the right lever; and a left linkage assembly operatively connecting the left actuator end to the left latch, the left linkage assembly comprising: a left lever pivotally mounted to the coupler frame proximate the left frame end, a left actuator link pivotally connected between the left actuator end and the left lever, and a left latch link pivotally connected between the left latch and the left lever.
 7. The coupling device of claim 6, wherein the right linkage assembly comprises a right spring disposed between the right latch and the right lever and biasing the right latch away from the right lever, and wherein the left linkage assembly comprises a left spring disposed between the left latch and the left lever and biasing the left latch away from the left lever.
 8. The coupling device of claim 6, wherein the left actuator link comprises an engagement slot configured to receive a prying tool for manipulation of positions of the variable length actuator, the right linkage assembly, the left linkage assembly, the right latch and the left latch.
 9. A method of coupling and decoupling an implement to and from a machine having a coupling device connected to lift arms of the machine, the method of coupling and decoupling comprising: moving the machine toward the implement and engaging an implement rear wall of the implement with a coupler frame front wall of a coupler frame; moving the coupling device to cause an implement engaging edge of the coupling device to be inserted into a coupler receiving bracket of the implement; and actuating a variable length actuator to extend to an actuator extended position and to correspondingly cause a right latch and a left latch operatively coupled to the variable length actuator to move to a latch locked position with the right latch and the left latch disposed within latch receiving openings of the implement, wherein the variable length actuator is operable to move between an actuator retracted position and the actuator extended position and is slidably mounted on the coupler frame so that a right actuator end and a left actuator end of the variable length actuator move horizontally relative to the coupler frame, and the variable length actuator does not move vertically relative to the coupler frame as the variable length actuator moves between the actuator retracted position and the actuator extended position.
 10. The method of coupling and decoupling of claim 9, comprising displaying a visual indication at the coupling device of an actuator position of the variable length actuator and a corresponding latch position of the right latch and the left latch.
 11. The method of coupling and decoupling of claim 10, wherein the coupler frame includes a coupler rear wall having a right horizontal guide slot and a left horizontal guide slot, wherein the variable length actuator comprises a right guide pin connected to the right actuator end and extending through the right horizontal guide slot and a left guide pin connected to the left actuator end and extending through the left horizontal guide slot, wherein the right horizontal guide slot and the left horizontal guide slot engage the right guide pin and the left guide pin, respectively, to cause the right actuator end and the left actuator end to move horizontally relative to the coupler frame and to prevent the variable length actuator from moving vertically relative to the coupler frame, and wherein the visual indication of the actuator position and the corresponding latch position is provided by pin positions of the right guide pin and the left guide pin within the right horizontal guide slot and the left horizontal guide slot.
 12. The method of coupling and decoupling of claim 9, wherein the variable length actuator is an extendable shaft assembly having a motor wherein the left actuator end is a left motor end operatively connected to the left latch, and a shaft extending from a right motor end of the motor and wherein the right actuator end is a right shaft end operatively connected to the right latch, and wherein actuating the variable length actuator comprises actuating the motor to extend the shaft to move the extendable shaft assembly to the actuator extended position.
 13. The method of coupling and decoupling of claim 9, comprising: to decouple the implement from the machine, actuating the variable length actuator to retract to the actuator retracted position and to correspondingly cause the right latch and the left latch to move to a latch unlocked position with the right latch and the left latch withdrawn from the latch receiving openings of the implement; and moving the coupling device to cause the implement engaging edge of the coupling device to move out of the coupler receiving bracket of the implement.
 14. A machine comprising: a cab; a right lift arm; a left lift arm; a coupler frame having a right frame end with the right lift arm coupled thereto and a left frame end with the left lift arm coupled thereto; a variable length actuator having a right actuator end and a left actuator end and extending between the right frame end and the left frame end of the coupler frame, the variable length actuator being operable to move between an actuator retracted position and an actuator extended position and being slidably mounted on the coupler frame so that the right actuator end and the left actuator end move horizontally relative to the coupler frame and the variable length actuator does not move vertically relative to the coupler frame as the variable length actuator moves between the actuator retracted position and the actuator extended position; a right latch slidably engaged by and movable relative to the coupler frame proximate the right frame end and operatively connected to the right actuator end of the variable length actuator; a left latch slidably engaged by and movable relative to the coupler frame proximate the left frame end and operatively connected to the left actuator end of the variable length actuator; and an implement having an implement rear wall engaged by a coupler frame front wall when the implement is coupled to the machine, wherein the right latch and the left latch move relative to the coupler frame between a latch unlocked position that will not engage the implement when the variable length actuator is in the actuator retracted position and a latch locked position that will engage the implement when the variable length actuator is in the actuator extended position.
 15. The machine of claim 14, wherein the coupler frame comprises: a right horizontal guide slot operatively connected to the right actuator end to cause the right actuator end to move horizontally relative to the coupler frame and to prevent the right actuator end from moving vertically relative to the coupler frame; and a left horizontal guide slot operatively connected to the left actuator end to cause the left actuator end to move horizontally relative to the coupler frame and to prevent the left actuator end from moving vertically relative to the coupler frame.
 16. The machine of claim 14, wherein the coupler frame comprises an actuator housing enclosing the variable length actuator and having a right horizontal guide slot and a left horizontal guide slot, wherein the variable length actuator comprises a right guide pin connected to the right actuator end and extending through the right horizontal guide slot and a left guide pin connected to the left actuator end and extending through the left horizontal guide slot, and wherein the right horizontal guide slot and the left horizontal guide slot engage the right guide pin and the left guide pin, respectively, to cause the right actuator end and the left actuator end to move horizontally relative to the coupler frame and to prevent the right actuator end and the left actuator end from moving vertically relative to the coupler frame.
 17. The machine of claim 16, wherein the right horizontal guide slot and the left horizontal guide slot extend through a housing rear wall of the actuator housing so that the right guide pin and the left guide pin are visible from the cab to provide an operator of the machine with a visual indication of a current position of the variable length actuator between the actuator retracted position with the right latch and the left latch in the latch unlocked position and the actuator extended position with the right latch and the left latch in the latch locked position.
 18. The machine of claim 14, wherein the variable length actuator is an extendable shaft assembly comprising: a motor wherein the left actuator end is a left motor end operatively connected to the left latch; and a shaft extending from a right motor end of the motor and wherein the right actuator end is a right shaft end operatively connected to the right latch, wherein the motor is actuatable to retract the shaft to move the extendable shaft assembly to the actuator retracted position and to extend the shaft to move the extendable shaft assembly to the actuator extended position.
 19. The machine of claim 14, comprising: a right linkage assembly operatively connecting the right actuator end to the right latch, the right linkage assembly comprising: a right lever pivotally mounted to the coupler frame proximate the right frame end, a right actuator link pivotally connected between the right actuator end and the right lever, and a right latch link pivotally connected between the right latch and the right lever; and a left linkage assembly operatively connecting the left actuator end to the left latch, the left linkage assembly comprising: a left lever pivotally mounted to the coupler frame proximate the left frame end, a left actuator link pivotally connected between the left actuator end and the left lever, and a left latch link pivotally connected between the left latch and the left lever.
 20. The machine of claim 19, wherein the right linkage assembly comprises a right spring disposed between the right latch and the right lever and biasing the right latch away from the right lever, and wherein the left linkage assembly comprises a left spring disposed between the left latch and the left lever and biasing the left latch away from the left lever. 